1. Field of the Invention
The present invention relates generally to electrical switch assemblies. More specifically, the present invention concerns a preferably waterproof switch having a uniform tactile feel.
2. Discussion of Prior Art
Those ordinarily skilled in the user actuatable switch assembly art will appreciate the broad utility of user depressible switch assemblies with one example of such assemblies being touchpad switch assemblies commonly used in the automotive industry. Notably, a user actuates such touchpad switch assemblies by depressing the touchpad a predetermined distance to engage a tact switch, elastomeric or metal dome switch, or the like. The switch is operably part of the final switch assembly and provides a tactile feel depending on the configuration and design of the switch. Importantly, a uniform tactile feel across the entire touchpad area is desired. Such uniformity may be difficult to obtain, however, because standard touchpad applications are sufficiently dimensioned to ensure actuation. In some instances, touchpad switch assemblies are configured to be operated by a plurality of fingers, such as, for instance, three fingers.
However, conventional large touchpad applications are problematic. For instance, if the assembly is provided with a single switch, actuation of the switch is not assured, particularly when one end of the touchpad is pressed by the user. With prior art switch assembly designs, the touchpad (or underlying actuator) can become canted or otherwise simply fail to actuate the switch. Furthermore, uneven movement of the shiftable portion of the switch assembly provides the user with unreliable tactile feedback as to whether the switch assembly has been actuated. Some conventional switch assemblies are provided with multiple switches spaced along the touchpad. However, this design requires signal debouncing when more than one of the switches is actuated by the user.
Moreover, as a result of the broad utility of user depressible switch assemblies, switch assemblies are exposed to, and must preferably withstand, a broad array of environmental and weather conditions. For instance, automotive touchpads experience large temperature ranges, rain, snow, and high-pressure car washes, thus requiring touchpads to be reliably sealed by employing various manufacturing techniques to protect the switch from such conditions, which may deteriorate and/or compromise the performance or functionality of the switch assembly. Sealing techniques are therefore preferable to protect the switch assembly and may be achieved by rubber and/or plastic over-molded parts, seal beading techniques, liquid adhesives, room temperature vulcanization techniques, epoxies, and the like. Application of such sealing techniques can, however, present manufacturing difficulties. For instance, reliable and repeatable sealing with epoxy presents challenges of consistently applying the epoxy in the desired sealing locations without presenting air bubbles and other voids that potentially denigrate the quality of the desired seal. Moreover, improved application of sealant commonly requires a moving applicator to appropriately seal various locations spaced apart on the switch assembly. But dynamic or moving sealant applicators introduce reliability and/or efficiency difficulties in the manufacturing process, which, again, may deteriorate and/or compromise the performance or functionality of the seal and, therefore, the switch assembly.